Benign skin lesions: Clinical sciences

Benign skin lesions are non-cancerous skin growths that are symmetrical in shape, color, and structure. They are typically stable with no change in appearance and no spontaneous bleeding. Benign skin lesions are classified by their cellular origin and include melanocytic, subcutaneous, keratinocytic, vascular, and fibrous.

Here’s a clinical pearl! Benign skin lesions are often diagnosed clinically. However, dermatologists may use other methods to help diagnose skin lesions. One tool is dermoscopy, which is a skin surface microscope that helps differentiate benign lesions from dysplastic and malignant lesions. Another option is skin biopsy either with shave, scissor, curettage, punch, or scalpel excision.

Now, if a patient presents with a chief concern suggesting a skin lesion, first obtain a focused history and physical examination. Your patient will report a growth on their skin, with no change in size, shape, or color. Physical exam will reveal a dermatologic lesion, which is typically symmetric, with a well-defined border, consistent coloration, and a diameter less than 6 millimeters. With these findings, diagnose a benign skin lesion.

Here’s a high-yield fact! When assessing a skin lesion, it's also important to know the features of a malignant skin lesion, like melanoma. Use the acronym ABCDE to help in your assessment. This stands for asymmetry, irregular borders, varying colors, diameter usually greater than 6 millimeters, and evolving in size, shape, or color. If any of these features are present, suspect a malignant skin lesion!

Your next step is to assess for a melanocytic lesion, most commonly a nevus! Your patient will report a pink, tan, or brown mole that hasn’t changed in size, shape, or color. There will also be no report of bleeding. Physical exam will reveal a flesh-colored, pink, tan, or brown papule that’s dome-shaped or pedunculated with a stem. It is typically soft or rubbery in texture. With these findings, diagnose nevus! Management of a nevus consists of monitoring for the development of malignant characteristics. If your patient prefers lesion removal for aesthetic reasons, this includes treatment like cryotherapy, shave excision, microdissection, or laser therapy.

Okay, next let’s evaluate for a subcutaneous lesion such as a lipoma! Your patient will report a mass under the skin in fatty areas of the body like the neck, trunk, and proximal extremities. Physical exam will show a soft, mobile, subcutaneous density with a rubbery texture. You may elicit the slippage sign, where on palpation, the density will slip from under the fingers when pressure is applied at the edge. With these findings, diagnose lipoma. No medical management is necessary, but again, if your patient prefers removal of the lesion, you might offer surgical excision.

Okay moving on, next assess for keratinocytic lesions which includes lentigo, seborrheic keratosis, sebaceous hyperplasia, actinic keratosis, and epidermoid cyst.

First up is lentigo! These patients will report a brown patch, and may have a history of fair skin, sun damage, phototherapy, or radiation therapy. Physical exam will show a pigmented flat or slightly raised lesion with a clearly defined edge. With these findings, diagnose lentigo. While there’s no specific medical management of lentigo, aesthetic treatment includes bleaching creams to lighten the discoloration or lesion removal with cryotherapy and laser therapy.

Next up is seborrheic keratosis! These patients report a brown, yellow, or gray growth that might be itchy or painful. Physical exam reveals a lesion with a dull, waxy surface with a “stuck on” appearance. With these findings, diagnose seborrheic keratosis. If the lesion causes your patient discomfort or if your patient prefers lesion removal, you can utilize cryotherapy, shave excision, electrocautery, or laser therapy.

Here's a high-yield fact! The abrupt onset of multiple seborrheic keratoses, known as the sign of Leser-Trelat, is a finding associated with the presence of an internal malignancy, such as gastrointestinal or pulmonary carcinomas!

Let’s move on to sebaceous hyperplasia! These patients report a growth on their face or upper trunk. They are often undergoing hormonal changes, such as menopause, or have a history of immunosuppressive therapy or antiretroviral medication use. Physical exam reveals a yellow or skin-colored dome-shaped papule with central umbilication. With these findings, diagnose sebaceous hyperplasia. If the appearance is bothersome, offer topical trichloroacetic acid or oral isotretinoin which can help fade the lesion. Alternatively, your patient may prefer to have the lesion removed with cryotherapy, surgical excision, electrocautery, or laser therapy.

Next up is actinic keratosis! These patients report a growth on a sun-exposed area of the body, often in the context of repeated sun exposure. The lesion might be itchy or painful. Physical exam shows erythematous macules, papules, or plaques with a rough, scaly texture. With these findings, diagnose actinic keratosis. Medical management is with topical agents like 5-fluorouracil, imiquimod, or diclofenac; or removal of the lesions with cryotherapy, laser therapy, or surgical excision.